It’s one of the most common complaints heard by veterinarians from desperate dog owners who don’t know how to rid their dog of smelly breath. Causes of bad breath in dogs include:

Oral health issues (tooth decay, gingivitis)

Diabetes

Kidney infection/disease

Gastrointestinal disorders

Upper respiratory infection)

Dietary abnormalities (tendency to eat garbage or fecal matter)

Tonsillitis/tonsil stool

Since chronic halitosis in dogs is usually indicative of a bacteria infection, dog probiotics is one of the most effective treatments for eliminating canine halitosis. Supplementing a dog’s diet with probiotics will restore healthy levels of beneficial bacteria in the intestines to enhance a dog’s overall health and prevent sulfur-producing anaerobic bacteria from breeding in the dog’s mouth.

Canine Oral Disease and Halitosis

Just like human bad breath, dog bad breath is caused by anaerobic bacteria, a species of bacteria that prefer low-oxygen, debris-filled environments such as a mouth full of plaque, tartar, mucous and infection. Ear and respiratory infections also contribute to anaerobic bacteria growth, which is why dog owners notice even worse bad breath in dogs with sinus and ear infections.

Dogs suffering periodontal disease will have visible yellowing of their teeth, especially near the gum line. This yellowing is called plaque, a combination of anaerobic bacteria, mucous, saliva and mouth debris that eventually hardens into tartar unless removed by a veterinarian. Tartar accelerates development of gum disease, receding gums, bleeding gums and painful abscesses. It also worsens bad breath since tartar is highly concentrated protein layers on which anaerobic bacteria thrive.

Canine halitosis is caused by anaerobic bacteria.

What are Anaerobic Bacteria?

Anaerobic bacteria secrete sulfur compound gases such as methyl mercaptan and hydrogensulfide that have been compared to the putrid odor of spoiled cabbage and rotten eggs. Other pungent molecules identified in anaerobic bacteria waste include volatile compounds called skatole, putrescine and cadaverine, which contribute to the foul odor of existing sulfur compounds.

When dogs develop tooth decay/loss, gum disease and oral abscesses, their oral pH level plunges. Low pH levels mean that high acidity exists, which promotes demineralization of canine teeth and softening of dental enamel. In addition, anaerobic bacteria stimulated by a reduced pH levels begin breeding exponentially by feeding on large amounts of proteins produced by increased mucous, worsening infections and any food debris remaining in the dog’s mouth.

Antibiotics Won’t Get Rid of Bad Breath in Dogs

Anaerobic bacteria are also highly resistant to antibiotics because they produce enzymes called β-lactamases. These enzymes encourage bacteria to evolve rapidly into slightly different bacteria that cannot be killed by antibiotics. Consequently, when dogs are repeatedly given antibiotics to treat a recurring respiratory or ear infection, the chronic nature of the infection is being perpetrated by ever-evolving anaerobic bacteria can resist antibiotics.

Anaerobic bacteria are highly resistant to antibiotics.

Canine Oral Yeast Infection and Bad Breath

When “bad” bacteria outnumber “good” bacteria in a dog’s body, fungal infections are much more likely to occur, especially in the mouth and on the skin. Oral fungal infections are notorious for causing extremely bad breath in dogs and typically emerge from the following conditions:

Breathing through the mouth due to sinus congestion, excessive panting or other condition that prevents the dog from breathing normally

Yellowish or whitish coating covering the inside of the mouth and tongue

Red patches that peel

Cracks at mouth corners

Patches that are slightly swollen and painful

Symptoms of Oral Yeast Infection

Bad breath that smells yeasty, stale and sour

Dogs suffering oral yeast infections due to an imbalance of bacteria in the body may develop more serious health issues, such as joint pain, chronic infections and even heart problems because of a compromised immune system that cannot fight disease adequately.

Tonsillitis and Tonsil Stones

Yes, dogs do have tonsils and they can get infected just like they do in humans. Systemic infections, frequent vomiting, oral disease and chronic coughing are common culprits of tonsillitis in dogs. In addition to causing bad breath, canine tonsillitis may also produce fever, drooling, a reluctance to drink or eat and visibly enlarged tonsils. Dogs can also suffer from tonsil stones, which are tiny, calcified pieces of bacteria, mucous and oral debris that form and lodge in the tonsils. Tonsil stones smell horribly (they do in humans, too) and smell even worse when they fall out and are accidentally chewed by the dog.

Canine tonsillitis can cause drooling.

Gastritis and Digestive Problems

Bad breath can also come from a dog’s gastrointestinal tract. Stomach inflammation and vomiting may occur if the dog has eaten something that irritates the stomach lining. Chronic gastritis accompanied by acid reflux not only destroys a dog’s esophageal tissues but also contributes to severe bad breath by providing anaerobic bacteria with even more protein-rich mucous to feed on.

Other GI tract disorders that may contribute to bad breath in dogs include colitis, gastrointestinal obstructions (tumors, polyps), ulcers and the presence of excessive helicobacteria, a type of antibiotic-resistant bacteria transmitted by insects (especially flies) and other dogs. A heliobacterial infection inflames the lining of the small intestines and stomach and will cause pain, vomiting and diarrhea. Dehydration and vomiting directly promote bad breath because of the powerful combination of a chronically dry mouth and vomit particles remaining in the dog’s mouth.

Treating Canine Halitosis with Probiotics

In addition to taking your dog to a veterinarian for yearly examinations and dental check-ups, giving your pet probiotic supplements as part of a healthy diet plan will prevent “bad” bacteria from dominating the GI tract and provoking the development of disorders causing bad breath. In addition, because probiotics suppresses growth of anaerobic bacteria, dogs taking them are less likely to suffer oral diseases and the bad breath associated with plaque, tooth decay and gum disease.

Disclaimer: the advice and information in this article is not intended to be used as a replacement for seeking medical attention if your dog has canine halitosis or other health issues.

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Doggy's Digest was started out of a love for canines and a need on the web for more information about probiotics for dogs. Our goal is to make this website the number one resource for optimizing your k9's digestive health and beyond!